Blowing-engine.



G. B. PETSCHE. BLOWING ENGINE. APPLICATION FILED JUNE 6, 1906.

Patented Feb. 16, 1909.

fl-i ATTORNEY.

UNITED STATES PATENT OFFIQE.

GUSTAV B. PETSOHE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO SOUTHWARKFOUNDRY AND MACHINE COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPO-RATION OF PENNSYLVANIA.

BLOWING-E NGINE Specification of Letters Patent.

Patented Feb. 16, 1909.

Application filed June 6, 1906. Serial No. 320,395.

To all whom it may concern:

Be it known that I, GUSTAV B. PETSCHE, a subject of the Emperor ofGermany, residing in the city and county of Philadelphia, in the Stateof Pennsylvania, have invented a certain new and useful Improvement inBlowing-Engines, of which the following is a true and exact description,reference being had to the accompanying drawings, which form a partthereof.

My invention relates to blowing engines or compressors of the kind inwhich the ports connecting the compressing cylinder and the receiver arecontrolled by valves actuated by auxiliary cylinders and pistons, thecylinders being connected with the compressing cylinders so that theincreasing pressure in said cylinder is transmitted to the face of theauxiliary piston to move it in a direction to open the delivery valve,the return movement of the piston and the closing of the valve isgenerally effected by some positively actuated part of the engine, suchas a cam.

The object of my invention is to regulate the admission of compressedair to the auxiliary cylinder so that the pressure in said cylinder willonly rise high enough to exert a substantial opening force on theauxiliary piston at or immediately before the point where the pressurein the compressing cylinder and receiver are equal. By proceeding inthis manner I avoid any injurious strains on the valve or valveactuating mechanism, and the leading feature of my invention consists inplacing in the conduit containing the compressing cylinder and auxiliarycylinder a normally seated valve arranged to open under the pressure ofair in the compressing cylinder and held to its seat by the pressure ofair in the receiver so that the valve will only open where the two pressures acting upon it bear a determined ratio to each other which is lessthan unity.

ther features of my invention will be best understood as described inconnection with the drawings in which it is illustrated and in whichFigure 1, is a side elevation of a portion of a compressing cylindershowing the valve actuating cylinders in section and such of theconnections therewith as are necessary for the understanding of mypresent invention. Fig. 2, is a sectional view of one of the valvecasings H, taken as on the section line 22 of Fig. 3, and Fig. 8 1s asectional view of the same valve casing taken on the I line 33 of Fig.2.

A, indicates the compressing cylinder; A, the compressing piston; B, B,the receivers at the ends of the cylinder; C, indicates the gridirondelivery valves controlling the ports at the delivery end of thereceiver.

C, is the valve stem which is connected to the piston D, having, asshown, a second piston extension D, connected with it; a cam roller Dbeing secured to the double piston between its two heads. The pistons,which are double headed pistons D, D, move in a double headed cylinderE, E, having lateral bearings E, on which moves a cam F, arranged tocontact with the cam roller D as indicated. The cams F, F, are shownconnected by a rod F, which are actuated by proper mechanism connectedwith the end F G, G, are conduits connecting the compressing cylinder A,with the cylinder ends E, E, as shown, and in this conduit are sit uatedthe valve casings II H, the construction of which is shown in Figs. 2and 8. The casings are provided with a partition K which supports twovalve seats, one indicated at L and the other at M. A movable head N, ofthe casing is formed with a cylinder N, opening downward and connectedat its upper end through the opening N with a pipe I, see Fig. 1,connecting in turn with the receiver D, of the engine.

O, indicates a removable head in the lower part of the casing H. P, themain valve normally seated on the seat L, and arranged to be acted upand held to its seat through a piston P, which may conveniently beformed integral with it as shown, and which works in the cylinder E. Alight spring Q should be provided to hold the valve to its seat.

R, is a valve normally seated on the seat M and held lightly to its seatby a spring K. It will be understood that the normal flow of compressedair from the compressing cylinder to the auxiliary cylinder is from theside J, to the side J, of the casing. Assuming the compressing piston tobe moving toward the left in Fig. 1, the valve C, at the left hand endof the cylinder is closed and the valve P, held firmly to its seat bythe pressure from the receiver B, connecting through the pipe I, withthe cylinder Q, and acting on the piston P. As the compressing pistonmoves toward the left the cam F, is withdrawn from contact with the rollD and the pressure accumulating in the compressing cylinder istransmitted to the under side of the valve P, the valve, however,remaining seated until this pressure has reached a determined ratio tothe pressure in the receiver at which point the valve P, will open andadmit the compressed air to the auxiliary cylinder E, where, acting onthe piston D, it effects a rapid opening of the valve C. The valve P andpiston extension P form in eflect a difierential piston of which thearea at the bottom end of the piston, exposed to the pressure of the,side J of the casing H is substantially greater than the area of the endof the piston working in the cylinder N As the spring Q is a lightspring, the valve P opens consequently when the ratio of the pressure inthe chamber J of the casing H to the pressure in the cylinder N isappreciably less than unity. By proceeding in this manner, it ispossible to prevent a rise in pressure in the valve actuating cylinder Eto a valve large enough to exert a strong opening force 011 the piston Duntil the instant, or but very slightly before the instant when thedelivery valve should open, while, on the other hand, the valve P opensearly enough in the stroke of the compressing piston to give time forair to pass into the cylinder E and build up the pressure therein at theproper instant to the point necessary to open the heavy delivery valve.

It will be understood by those skilled in the art that the ratio betweenthe pressure in chamber J and cylinder N at which the valve P shouldopen, will depend to some extent on the speed at which the engine isrun. The light spring Q is therefore so chosen for any particularcondition of use as to insure that the valve P will open when thepressure in the seat J of the casing H rises to a ratio with thepressure in the cylinder N which is proper under the circumstances. Assoon as the compressing piston has crossed and uncovered the opening ofthe conduit G, into the cylinder the pressure behind the piston ofcourse falls to atmospheric or less than atmospheric pressure and thecompressed air in the cylinder E, can then escape back into the cylinderby raising the valve R, from its seat, and thus enables the valve C, tobe closed by the action of the cam F, without undue compression of theair in the cylinder E. The function of the cylinder end E, and pistonhead D, is simply to serve as a cushioning device in the opening of thedelivery valves, the construction being described in former patents andformingno part of my present invention.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. The combination in a blowing engine having a compressing cylinder, areceiver, a delivery valve opening and closing communication betweensaid cylinder and receiver, an actuating piston and cylinder for thedelivery valve, a conduit connecting the valve actuating and compressingcylinders, and means responsive to the pressure in the receiver andcompressing cylinder for preventing air from passing through saidconduit to the valve actuating cylinder to open the delivery Valveexcept when the ratio of the pressure in the compressing cylinder to thepressure in the receiver rises to a predetermined value which isappreciably less than unity.

2. The combination in a blowing engine having a compressing cylinder, areceiver, a delivery valve opening and closing communication betweensaid cylinder and receiver, an actuating piston and cylinder for thedelivery 90 valve, a conduit connecting thevalve actuating andcompressing cylinder, means responsive to the pressure in the receiverand compressing cylinder for preventing air from passing through saidconduit to the valve actuating cylinder toopen the delivery valve exceptwhen the ratio of the pressure in the compressing cylinder to thepressure in the receiver rises to a predetermined value which isappreciably less than unity, and Y means 100 acting independently of thereceiver pressure for permitting air to flow through said conduit fromthe valve actuating cylinder to the compressing cylinder.

3. In a blowing engine having a receiver, 105,

a gridiron delivery valve opening thereto and a valve actuating cylinderconnected to the compressing cylinders as described, a normally seatedvalve situated in the conduit leading from the compressing cylinder tothe valve actuating cylinder, said valve having a surface acted on bythe pressure of the air in the compressing cylinder in a directiontending to open said valve, and means for holding the valve to its seatcomprising a piston surface smaller than the first mentioned surface andacted on by the pressure of the receiver.

4. In a blowing engine having a receiver, a gridiron delivery valveopening thereto and a valve actuating cylinder connected to thecompressing cylinders as described, a normally seated valve situated inthe conduit leading from the compressing cylinder to the valve actuatingcylinder, said valve having a surface acted upon in a direction to openthe valve by the pressure of the air in the compressing cylinder, meansfor holding the valve to its seat comprising a piston surface smallerthan the first mentioned surface 13 acted on by the pressure in thereceiver and means for permitting the escape of air from the actuatingcylinder during the closing of the delivery valve.

5. In a blowing engine having a receiver, a delivery valve openingthereto, and a valve actuating cylinder connected to the compressingcylinder as described, a conduit leading from the compressing cylinderto the valve actuating cylinder, and means regulating the fiow of airfrom the compressing cylinder to the valve actuating cylinder throughsaid conduit, said means comprising a differential piston having itslarger end acted on in the direction to open the conduit by the pressurein the compressing cylinder, and its smaller end acted on in thedirection to close the conduit by the pressure of the receiver, and alight spring also acting on said piston in a direction to close saidconduit.

6. In a blowing engine having a receiver, a delivery valve openingthereto and a valve actuating cylinder connected to the coinpressingcylinders as described, a valve casing H, situated in the conduitconnecting the compressing cylinder and valve actuating cylinder, saidcasing having a main seat L, and supplemental seat M, and a cylinder N,in combination with a conduit connecting cylinder N with the receiver, apiston working in cylinder i a valve P, acted on by said piston andnormally closing seat L, and a normally seated valve R, closing seat M.GUSTAV B. PETSCHE. Witnesses:

ARNOLD KATZ, S. STEWART.

